1. Technical Field
The present invention relates to a plate-like apparatus, integral rotating body device, and disk device, which are used as a magnetic data storage and retrieval system.
2. Description of the Related Art
Various devices, ranging from data processing systems to optical data capture systems, employ portable or removable storage media to accommodate and retain data. The last few years have witnessed an ongoing and well-publicized effort toward miniaturizing and increasing the capacity of these storage media.
Much of the development in the miniaturization and capacity improvement of storage media has resulted in improvements in magnetic data storage and retrieval systems, commonly referred to as hard disk drives. A magnetic data storage and retrieval system frequently comprises an annular, magnetic disk for storing data (hereinafter simply referred to as a xe2x80x9cdiskxe2x80x9d), a spindle motor, which rotates the disk, a read/write head, which reads/writes data from/to the disk, an actuator, which drives the read/write head in a direction radial to the disk, and other, related equipment and circuitry.
Attempts to miniaturize magnetic data storage and retrieval systems have required very precise construction of mechanical structures such as the disk, spindle motor, read/write head, and actuator. Accordingly, mechanical shock events such as dropping or bumping the magnetic data storage and retrieval system against a solid object frequently result in malfunctions. In particular, mechanical shock events that result in a misalignment of the disk with respect to the center of rotation of the spindle motor may compromise the ability of the read/write head to read or write data from or to the disk.
Common disk designs connect the rotating shaft of the spindle motor to the disk through the disk""s central hole. The size of the central hole is designed to allow a clearance (between the inner edge of the disk and the rotating shaft of the spindle motor) for ease of insertion during assembly. Clamp, screw, or other articulating hardware affixes the disk to the rotating shaft of the spindle motor. Data is recorded on the disk by the read/write head while the disk is rotated by the spindle motor. This is accomplished by recording the data in concentric tracks. If a shock event of a magnitude greater than the magnitude of the frictional forces between the disk, the rotating shaft, and the articulating hardware occurs, the center of the disk may become displaced within the clearance between the disk and the rotating shaft with respect to the center of rotation of the spindle motor. As a result, the read/write head may be unable to read or write data from or to the disk.
The proposed, partial solution discussed in Published Unexamined Patent Application No. 11-353865 deals with the displacement problem by mounting bumpers, composed of an elastic material, on corner portions of a magnetic data storage and retrieval device. If the magnetic data storage and retrieval device is dropped, the bumpers can absorb the energy of the shock event to prevent the displacement of the disk. In a magnetic data storage and retrieval system shaped as a rectangular plate of predetermined thickness, such as Compact Flash (a registered trademark), such bumpers are naturally most effective when attached to the four corners of the magnetic data storage and retrieval system.
The example of Compact Flash, however, illustrates the deficiencies, limitations, and inadequacies of the prior art. Compact Flash calls for a guide groove on each side, thereby allowing mounting on a data processing system, a unit of peripheral equipment such as digital camera, or an articulating adapter. The technique described in the above referenced publication fails to accommodate this guide groove. Further innovations in the design of magnetic data storage and retrieval systems are necessary in order to allow the technique described above to effectively accommodate the requirements of guide-groove designs such as Compact Flash.
Examination of the problem described above indicates that, as shown in FIG. 15, the magnetic data storage and retrieval system 1 attached to a data processing system or peripheral device, and the guide portion 3 on the adapter side include a guide groove 2 corresponding to the projection 4 of the guide 3 so that at least one end thereof continues to the corner of the magnetic data storage and retrieval system 1. Attachment of a bumper 5 to the corner requires formation of a groove portion 6 corresponding to the guide 2.
However, because the bumper 5 is usually formed from an elastomeric material to achieve shock absorbing properties, it is difficult to size the groove portion 6 (S in FIG. 15) precisely when the bumper 5 is molded. As shown in FIG. 16A, if the size S of the groove portion 6 is substantially smaller than the size of the guide groove 2, substantial friction exists between the groove portion 6 of the bumper 5 and the projection 4 of the guide portion 3 when the magnetic data storage and retrieval system 1 is inserted into or removed from the guide portion 3. This friction complicates insertion and removal of the magnetic data storage and retrieval system by requiring substantial force to overcome the frictional force at insertion and removal. Further, as shown in FIG. 16B, if the size S of the groove portion 6 is excessively large relative to the size of the guide groove 2, the projection 4 of the guide portion 3 can be blocked by the step 7 between the groove portion 6 of the bumper 5 and the guide groove 2 when the magnetic data storage and retrieval system 1 is set in the guide portion 3.
The present invention solves the problems described above, and its object is to provide a plate-like apparatus, integral rotating body device, and magnetic data storage and retrieval system, which can absorb the energy of an external shock event and can be easily attached.
The plate-like apparatus of the present invention, designed to account for the problems described above, is attachable to and detachable from a loading object having a pair of guide portions, and it has a guide groove on each side of the rectangular plate-like apparatus body. In the two corners where these guide grooves are formed, a shock absorbing member projecting beyond the apparatus body is provided on one side in the thickness direction of the apparatus body. If such a plate-like apparatus is dropped, the projection of the shock absorbing member beyond the apparatus body causes it to contact the impact surface before the remainder of the apparatus body. This design can effectively absorb the shock applied to the whole apparatus.
As an example of such a plate-like apparatus, consider one constructed so as to comply with the Compact Flash standard, and as an exemplary loading object, consider various devices such as a data processing system, a digital camera, or a memory player. One can also envision application of the present invention to an adapter used to attach the plate-like apparatus to various devices, such as a PC card.
Such a plate-like apparatus has a pair of guide grooves for attachment to the loading object, and each guide groove is formed so that at least one end thereof reaches a corner of the apparatus body. Both ends of the guide groove may reach the corners of the apparatus body. In the case where both ends of the guide groove reach the corners of the apparatus body, the design need only provide shock absorbing members in the corners at both ends. If only one end of the guide groove reaches the corner of the apparatus body, another shock absorbing member, covering a whole corner, may be provided in the remaining two corners where no guide groove exists.
Another consideration arises from the fact that, in Compact Flash and similar devices, the guide grooves formed in the two sides of the plate-like apparatus have different widths. Such a design may require pedestal surfaces meeting the guide grooves. Both pedestal surfaces can be simultaneously processed, making the manufacturing of the plate-like apparatus more efficient. Projection of the shock absorbing member into the guide groove can be avoided if a step portion corresponding to the groove width of the guide groove is formed in the shock absorbing member before it is attached to the pedestal surface.
Such a plate-like apparatus is set in the loading object, resting on the side opposite to one side where the shock absorbing member is provided.
The integral rotating body device of the present invention comprises a shock absorbing member in the corner of an enclosure. The enclosure contains a rotating body, and in the corner, the shock absorbing member is exposed in part of the thickness direction of the enclosure. The enclosure itself is exposed in the remainder of the thickness direction of the enclosure, and the enclosure is located inward from the shock absorbing member.
More specifically, the integral rotating body device may have a structure in which a spindle for rotating the rotating body is inserted into the hole of the rotating body at a predetermined clearance.
By providing the shock absorbing member in the integral rotating body device, the rotating body can be prevented from becoming misaligned with respect to the spindle. And, by locating the enclosure inward from the shock absorbing member, the shock absorbing member lands first when the device is dropped.
To locate the enclosure inward of the shock absorbing member in the corner, a chamfer may be formed in the enclosure.
If the integral rotating body device falls and lands on its corner, the shock given to the rotating body becomes maximized when the rotating surface of the rotating body is positioned on the body""s vertical line. Accordingly, if the chamfer is formed orthogonal to the line connecting the corner and the center of rotation of the rotating body, the chamfer lands in an orientation that will minimize this shock more frequently than if the chamfer were formed at another angle. This chamfer design increases the shock absorption.
Moreover, the integral rotating body device does not always fall with the rotating surface of the built-in rotating body vertically oriented. It may fall at angle to the vertical plane. A chamfer located at one side in the thickness direction of the enclosure and a shock absorbing member located on the other side in the thickness direction of the enclosure are then effective solutions to maximize shock absorption. If the integral rotating body device falls at an angle and with the one side down, the shock absorbing member on the other side lands first (unless a predetermined angle of orientation relative to the vertical axis is exceeded) because the chamfer is formed inward from the shock absorbing member on the one side. The shock can then be absorbed.
The present invention includes a magnetic data storage and retrieval system comprising a base, including a magnetic disk, and having a guide groove in the outside surface thereof It also includes a plate-like corner member set at a corner of the base and formed from a material softer than the base. In the plate-like corner member, the groove wall surface on one side (separated by the guide groove) is constructed with the base, while the groove wall surface on the other side is constructed with the corner member. The base can be characterized by further including a read/write head for reading/writing data to the magnetic disk, and an actuator for moving the read/write head.
Thus, the force and energy of a shock event can also be absorbed by the plate-like corner member formed from a material softer than the base, and the magnetic disk can be prevented from becoming misaligned.
The corner member may be formed from an elastic material.
In magnetic data storage and retrieval system of the present invention, the base has a projection projecting sideward from the built-in portion, including the magnetic disk, and the corner member can be attached and fixed to the projection by an attachment member. Further, the attachment member may have a predetermined length, and comprise a pressing portion for pressing the corner member at one end thereof, and an abutting portion abutting on the projection at the other end. Since this attachment member has a predetermined length, the pressing portion is located at a predetermined height with the abutting portion abutting on the projection of the base. The corner member can thereby be prevented from being excessively pressed by the pressing portion. This can prevent the corner member from expanding sideward, even if the corner member is formed from an elastomeric material.
Further, a second corner member maybe inserted into a second corner of the base at an insertion groove formed in the corner where the above corner member is not attached. In this case, by affixing a label covering at least part of the second corner member to the magnetic data storage and retrieval system, the second corner member can be prevented from dislodging.